Well I have most boxes checked I guess, the ones on my list anyway. And please, these are opinions and mine is no better than yours.
1. A .22 rifle is probably the most important gun anyone can own IMO. I prefer levers but I do have a 10/22. But any good .22 really, and 5,000 rounds of quality ammo and that would serve about 90% of any persons "needs" as well as anything.
2. A Glock 19. I have several 9mm handguns, just me talking out my hat here, but if you make a list of all important aspects of a combat pistol it's just really hard to beat all around. Any reliable semi-auto could fill this slot, the G19 is my choice.
3. A 12 gauge shotgun. Honestly probably the Remington model 870. I have an 1100, but for self defense and hunting I think the 870 would be my choice.
4. An AR-15. You could substitute other semi-auto combat guns, but why?
5. A bolt-action centerfire. Really tough to beat the .308 in this regard IMO. I have a half-dozen calibers, but the .308 is the best all around hunting cartridge in the lower 48.
The second 5 become must haves for everyone that has the first five covered.
6. A 1911 pistol in .45 ACP - Your first should be a Colt.
7. A Colt or a S&W pre-lock magnum revolver.
8. A centerfire lever action rifle.
9. M1A
10. Another 1911.